I could see a certain demographic using it for target practice.
Schroedinger’s Art Installation: It was on exhibit only as long as no one was able to see it. Once people could see it, it disappeared.
I believe it’s also called the Theory of Obscurity:
In 1978, the official word was that The Residents had stated that [the album] Not Available could never be released. The group claimed that they had recorded the album in secrecy as a way of exercising their Theory of Obscurity to its fullest and, in strict accordance with the Theory, the work could never be released until its creators no longer recalled its existence.
Yeah, that’s sort of confusing. I mean, the object would be some sort of private property, in the sense of “this thing must have belonged to someone before being put here”, but I don’t see how that would preclude the BLM from removing an unauthorized structure and then trying to locate the owner to recover costs and assess penalties.
Cutting into the rocks to install a semipermanent structure (apparently there since at least 2016) almost certainly requires a permit.
At my high school it was announced, from time to time, that “The Enigma Society will not be meeting this week.” And as far as I know, it never did.
From the BLM
Official statement: “Although we can’t comment on active investigations, we would like to remind public land visitors that using, occupying, or developing the public lands or their resources without a required authorization is illegal, no matter what planet you are from.”
And the excavation of the sandstone required to install the monolith is destruction of property.
No story I’ve seen on this has pointed out that, in Clarke’s original story “The SEntinel”, the alien artifact was more like a pyramid. They changed it to a monolith for the film to be more vuisually impressive. As Arthur C. Clarke himself said:
So apparently the jokers responsible for switching the obelisk that was there for a pyramid were hip to the backstory of 2001
But they forgot the forcefield. People always seem to forget the forcefield. What’s up with that? 
Was sandstone excavated? I missed that part . . . I assumed they just dug a hole in some ‘valley sand.’
Tripler
If it’s gone, all’s well that ends well, no?
It was embedded in solid sandstone. There were saw marks at the corners shown in one of the videos up-thread. Like, where you have to cut past the corner to get the full depth as far as you want.
I stand corrected then. Thank you!
I am surprised at “saw marks.” I would have reckoned phaser/disruptor scorchmarks.
Tripler
Saw marks tell me our Reticulan friends are into DIY home repair, then.
They weren’t on sale at Home Depot this week.
If there’s any switch or button on its, for the love of God, DON’T PRESS IT! 
Seconded. I speak from professional experience.
Tripler
It could be one shiny, triangular hell of a UXO.
You mean like this documentary on properly defeating a UXO?
Spot on. A perfect operation, in my humble opinion.
Tripler
Of course, one should always be just as cautious when dealing with silverplated items.
In fighters we always took a certain comfort in the idea that if we got hit or crashed:
Well, it won’t hurt for long.
I assume EOD folks share a similar mindset, whether the object of your attentions is silver plated or not.
Reminds me of a hoary joke told about campfires in the Old West:
Stupid white man build large fire sit way back.
Smart red man build small fire sit close.
When dealing with silverplate problems as Chief Brody almost said to Cap’n Quint:
We’re gonna need a much longer screwdriver.
Don’t worry. Those things don’t go off unless you hit them just right.
Our motto is: “Initial success, or total failure.”
@DPRK, one of my going away gifts when I left active duty for my present job, was a mallet stencilled “Dud Tester.”
Tripler
Good times, good times.
This is so stinking cool! Another one in Romania!